How redundant information can help overcome bias (joint with Nicolás Figueroa and Rubén Jara) (previously circulated as "Communication through biased intermediators")
Abstract: An organization with access to data delegates its empirical analysis on a possibly biased expert. We find that, by adding redundant information and privately manipulating the data (e.g., by secretly switching data entries), the organization is able to completely neutralize the bias of the expert; it is as if the expert is unbiased. We discuss how our results can be used to increase the transparency of empirical research with particular emphasis on the medical research over the effects of certain drugs.
Assignment mechanisms with state-independent preferences and independent types (online appendix)
Abstract: I study a general mechanism design problem without transfers under two assumptions: that agents have state-independent preferences and statistically independent types. I characterize optimal mechanisms for the one-agent and multiple-agent cases, discuss the value of commitment power for the decision maker and prove a comparative statics' result. As an application, I consider the optimal design of peer-review contests when jurors are biased. I argue that quotas, where each academic field is assigned a fixed number of prizes, are not optimal, and that asking reviewers to review applications from other fields may actually increase the expected quality of the prize recipients.
Can impartial peer-review mechanisms replace external reviewers?
Abstract: The increase in the number of academic competitors for grants and conferences makes it unfeasible to continue to rely exclusively on external reviewers for peer evaluation. An alternative is to ask applicants to rate each other using impartial mechanisms which eliminate the incentives to misreport of self-interested applicants. I introduce the reliable subset mechanism and argue that, for most academic contests, this impartial mechanism performs similarly to using external reviewers, provided the applicants are as capable of generating accurate reviews. I then show that external reviewers are rendered unnecessary altogether whenever evaluations of the same applicant are strongly correlated.
Slave Trade and the Spread of Islam in Africa: Theory and Evidence (joint with Akwasi Ampofo, Umair Khalil and Laura Panza)
Abstract: We investigate an overlooked legacy of the Atlantic slave trade: its indirect role in the spread of Islam in West Africa. We develop a theoretical model to study the dynamics of religious conversion in the face of a changing payoff structure, induced by the introduction of the slave trade. Islamic rulers protected Muslims against enslavement, creating an incentive for conversion among non-Muslims. Coupled with non-linear private returns in the share of co-religionists and intergenerational transfer of religion, our model delivers the existence of multiple, stable steady-states for the share of Muslims in a community, theoretically rationalizing the contemporary religious landscape in West Africa. We assemble newly sourced historical data as well as contemporary survey-based measures on the regional presence of Islam to provide empirical support for our model of religious conversion. This analysis reveals that communities under Islamic rule during 1500-1800 and exposed to Atlantic slavery exhibited differentially higher Muslim presence both after the end of slavery and today.